Not a month after releasing her 2009 debut, Elly Jackson was struggling to live up to the steely image she created as the androgynous leader of La Roux. Then, 21 years old and on her first US tour, the Londoner played a tiny Castro club where San Francisco’s synthpop cognoscenti eagerly checked out the act already considered the rightful heir to Yaz and Eurythmics. Patently terrified of the crowd within arm’s length, Jackson greeted their enthusiasm with solemn, fear-stricken stiffness — not the right stance for a woman best known for a song in which she vows to become emotionally indestructible.

A full year later, “Bulletproof” went double platinum, a feat that similarly fashioned European hits by Annie, Little Boots, Goldfrapp, Robyn, and other deserving peers couldn’t approach. But instead of capitalizing on that success, Jackson snapped. She’d reach mid-concert for the falsetto high notes that give “In for the Kill” and other tracks their keening impact, and nothing would come out. Then she butted heads with sole La Roux cohort Ben Langmaid: Multi-instrumentalist Jackson wanted to mine rare disco grooves; her co-writer/producer resisted until the duo split acrimoniously. Eventually, Jackson soldiered on, finishing up what they started with engineer Ian Sherwin, and then bigger pros like Jay-Z vets Al Shux and Jeff Bhasker. The resulting five-year gap between La Roux and what’s finally become her next album is for dance-pop an eternity: The freshmen whose parties “Bulletproof” soundtracked have already graduated.

As its title suggests, Trouble in Paradise addresses this turbulence. Although Jackson avoids direct autobiography, she’s been candid about the album’s theme: “the feeling of emptiness in a place where there was once joy.” Gone are the staccato synth stabs that gave her first album its early ’80s accuracy. Instead, there are other Thatcher/Reagan-era modes: Opening track “Uptight Downtown” nicks Nile Rodgers’ guitar scratching in David Bowie’s “Let’s Dance.” She’s abandoned the intimacy of a lonely girl and her machines for full-band funk, and where her vocals had been dry and often solitary, here they’re overdubbed into an airy choir resembling that of Tina Weymouth and her sisters of the Tom Tom Club. When Jackson sings of England’s 2011 riots, the vibe is tense, the rhythms rattle, and she drops out and fades back in with dub’s surreal trickery. Her sessions with a confidence-boosting specialist clearly paid off.

This is a record that’s rarely reggae but often informed by it — the spaciousness between notes, the reverberations in the rhythms, the overt studio consciousness. Like the punk-ska bands, Jackson paces most everything faster and more energetically than the Rastas, as if she’s never touched a spliff, and that tension suits her: On “Kiss and Not Tell,” she dances around speculation on her sexuality. “All along I’ve had feelings I can’t help . . . and all I want is to come out of my shell,” she teases as the jump-rope disco builds, breaks down, and rises once again with a playful piano tickle, another Chic-schooled guitar stutter, finger snaps where there would be snare, and an even stronger one-woman chorus. It’s all a tease: She’s saying everything by revealing nothing, as Sherwin shuffles the hooks and then stacks them on top of each other to drown out questions unanswered.

Jackson depicts physical desire as both liberating and shackling, illusory and painfully real. “Oh you make me happy in my everyday life/ Why must you keep me in your prison at night,” she trills in “Cruel Sexuality.” She’s not just talking about orientation. In “Sexotheque,” she juxtaposes traditional gender roles over beats and riffs borrowed from Grace Jones’ urbane island funk: A husband craves promiscuity, his wife wants to settle down. Each leaves the other hungry for what they lack — there’s only silence, “no one’s around” — while the carnival melody suggests the freedom their conflict denies. Without her beloved in “Paradise Is You,” a palm-lined beach is “nothing nice.” The titular character in “Tropical Chancer” — Paradise’s most Anglo-Jamaican cut — ultimately proves himself just a gigolo. And in the album’s most dramatic turn, “Let Me Down Gently,” a brooding ballad that pauses then shifts into an equally aching, sax-squealing throb, there’s only lofty expectations and crushing disappointments. “Turn me into someone good,” she cries in a voice both childlike and bruised.

Jackson writes open-endedly, shifting between direct experience and metaphor; mysteries left unsolved by her lyrics and persona are alternately heightened and resolved by the hurt in her voice, the assuredness of her arrangements. Nowhere is this most apparent than in the peak-hour dance track, “Silent Partner.” She might be singing about a lover, but she’s probably lashing back at Langmaid. “You’re not my partner/ No, you’re not a part of me,” she seethes as an archetypal hi-NRG bass line pumps and pounds for seven carb-burning minutes while Sherwin mixes the track so that it rises, falls, and elevates again to sustain her rage. An unabashed ’80s flashback to gay club anthems by Dead or Alive, Bronski Beat, and Bananarama all rolled into one sweaty ball of leather-clad, mustachioed macho, it’s the rare retro tribute that manages to match the hit-hungry euphoria of its sources. There’s so much frustration being released here that Jackson cannot hide her glee.